Fix release: bump Python from 3.9 to 3.12 [ignore-release] (#45) GitHub Actions runners no longer ship Python 3.9, so the Setup Python step in the SDK publish job failed with "Version 3.9 with arch x64 not found", canceling the whole release. Bump the SDK publish matrix to Python 3.12, matching the version already used in ci.yml (3.12.2).